Variability in a Mixed Layer Ocean Model Driven by Stochastic Atmospheric Forcing

1996 ◽  
Vol 9 (10) ◽  
pp. 2424-2442 ◽  
Author(s):  
Michael A. Alexander ◽  
Cecile Penland
Keyword(s):  
Mixed Layer ◽  
Ocean Model ◽  
Atmospheric Forcing ◽  
Model Driven ◽  
Mixed Layer Ocean

A numerical study on the role of atmospheric forcing on mixed layer depth variability in the Bay of Bengal using a regional ocean model

2021 ◽  
Author(s):  
Sumit Dandapat ◽  
Arun Chakraborty ◽  
Jayanarayanan Kuttippurath ◽  
Chirantan Bhagawati ◽  
Radharani Sen
Keyword(s):  
Mixed Layer ◽  
Bay Of Bengal ◽  
Numerical Study ◽  
Mixed Layer Depth ◽  
Ocean Model ◽  
Atmospheric Forcing ◽  
Layer Depth ◽  
Regional Ocean Model

scholarly journals SST Variability and Its Mechanism in a Coupled Atmosphere–Mixed Layer Ocean Model

1999 ◽  
Vol 12 (5) ◽  
pp. 1221-1239 ◽  
Author(s):  
Akio Kitoh ◽  
Tatsuo Motoi ◽  
Hiroshi Koide
Keyword(s):  
Mixed Layer ◽  
Ocean Model ◽  
Sst Variability ◽  
Mixed Layer Ocean

A New Solar Radiation Penetration Scheme for Use in Ocean Mixed Layer Studies: An Application to the Black Sea Using a Fine-Resolution Hybrid Coordinate Ocean Model (HYCOM)*

2005 ◽  
Vol 35 (1) ◽  
pp. 13-32 ◽  
Author(s):  
A. Birol Kara ◽  
Alan J. Wallcraft ◽  
Harley E. Hurlburt
Keyword(s):  
Solar Radiation ◽  
Optical Depth ◽  
Black Sea ◽  
Ocean Circulation ◽  
Mixed Layer ◽  
Ocean Model ◽  
The Black Sea ◽  
Atmospheric Forcing ◽  
Model Simulations ◽  
Hybrid Coordinate Ocean Model

Abstract A 1/25° × 1/25° cos(lat) (longitude × latitude) (≈3.2-km resolution) eddy-resolving Hybrid Coordinate Ocean Model (HYCOM) is introduced for the Black Sea and used to examine the effects of ocean turbidity on upper-ocean circulation features including sea surface height and mixed layer depth (MLD) on annual mean climatological time scales. The model is a primitive equation model with a K-profile parameterization (KPP) mixed layer submodel. It uses a hybrid vertical coordinate that combines the advantages of isopycnal, σ, and z-level coordinates in optimally simulating coastal and open-ocean circulation features. This model approach is applied to the Black Sea for the first time. HYCOM uses a newly developed time-varying solar penetration scheme that treats attenuation as a continuous quantity. This scheme includes two bands of solar radiation penetration, one that is needed in the top 10 m of the water column and another that penetrates to greater depths depending on the turbidity. Thus, it is suitable for any ocean general circulation model that has fine vertical resolution near the surface. With this scheme, the optical depth–dependent attenuation of subsurface heating in HYCOM is given by monthly mean fields for the attenuation of photosynthetically active radiation (kPAR) during 1997–2001. These satellite-based climatological kPAR fields are derived from Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) data for the spectral diffuse attenuation coefficient at 490 nm (k490) and have been processed to have the smoothly varying and continuous coverage necessary for use in the Black Sea model applications. HYCOM simulations are driven by two sets of high-frequency climatological forcing, but no assimilation of ocean data is then used to demonstrate the importance of including spatial and temporal varying attenuation depths for the annual mean prediction of upper-ocean quantities in the Black Sea, which is very turbid (kPAR > 0.15 m−1, in general). Results are reported from three model simulations driven by each atmospheric forcing set using different values for the kPAR. A constant solar-attenuation optical depth of ≈17 m (clear water assumption), as opposed to using spatially and temporally varying attenuation depths, changes the surface circulation, especially in the eastern Black Sea. Unrealistic sub–mixed layer heating in the former results in weaker stratification at the base of the mixed layer and a deeper MLD than observed. As a result, the deep MLD off Sinop (at around 42.5°N, 35.5°E) weakens the surface currents regardless of the atmospheric forcing used in the model simulations. Using the SeaWiFS-based monthly turbidity climatology gives a shallower MLD with much stronger stratification at the base and much better agreement with observations. Because of the high Black Sea turbidity, the simulation with all solar radiation absorbed at the surface case gives results similar to the simulations using turbidity from SeaWiFS in the annual means, the aspect of the results investigated in this paper.

scholarly journals A One-Dimensional Mixed Layer Ocean Model for Use in Three-Dimensional Climate Simulations: Control Simulation Compared to Observations

2005 ◽  
Vol 18 (13) ◽  
pp. 2199-2221 ◽  
Author(s):  
Monica Y. Stephens ◽  
Robert J. Oglesby ◽  
Martin Maxey
Keyword(s):  
Heat Flux ◽  
Mixed Layer ◽  
General Circulation ◽  
Climate Model ◽  
Mixed Layer Depth ◽  
Circulation Model ◽  
Ocean Model ◽  
Ocean Dynamics ◽  
One Dimensional ◽  
Mixed Layer Ocean

Abstract A study has been made of the dynamic interactions between the surface layer of the ocean and the atmosphere using a climate model that contains a new approach to predicting the sea surface temperature (SST). The atmospheric conditions are simulated numerically with the NCAR Community Climate Model (CCM3). The SST is determined by a modified Kraus–Turner-type one-dimensional mixed layer ocean model (MLOM) for the upper ocean that has been coupled to CCM3. The MLOM simulates vertical ocean dynamics and demonstrates the effects of the seasonal variation of mixed layer depth and convective instability on the SST. A purely thermodynamic slab ocean model (SOM) is currently available for use with CCM3 to predict the SST. A large-scale ocean general circulation model (OGCM) may also be coupled to CCM3; however, the OGCM is computationally intensive and is therefore not a good tool for conducting multiple sensitivity studies. The MLOM provides an alternative to the SOM that contains seasonally and spatially specified mixed layer depths. The SOM also contains a heat flux correction called Q-flux that crudely accounts for ocean heat transport by artificially specifying a heat flux that forces the SOM to replicate the observed SST. The results of the coupled MLOM–CCM3 reveal that the MLOM may be used on a global scale and can therefore replace the standard coupled SOM–CCM3 that contains no explicit ocean dynamics. Additionally, stand-alone experiments of the MLOM that are forced with realistic winds, heat, and moisture fluxes show that the MLOM closely approximates the observed seasonal cycle of SST.

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